Security readout for executives and security teams
Plain-English summary
A Linux VFIO PCI error-handling flaw can free memory twice when file descriptors are exhausted. A local, low-privileged user may be able to cause serious confidentiality, integrity, or availability impact. Exposure depends on the affected kernel code and VFIO PCI dma-buf feature being present.
Executive priority
Treat as a high-priority kernel maintenance issue on virtualization or device-passthrough systems. Accelerate assessment where untrusted local users can access VFIO functionality. Broader fleets without that exposure can follow risk-based patching after confirming vendor applicability.
Technical view
vfio_pci_core_feature_dma_buf() can fall through its unwind chain after a dma-buf-related failure. Under file descriptor exhaustion, this may unbalance the VFIO device reference count and double-free allocated objects. The published correction moves dma_buf_put() into the appropriate error path and returns the error directly.
Likely exposure
Prioritize Linux systems using VFIO PCI and its dma-buf feature, especially where untrusted local users have access. The bundle identifies the Linux 6.19 line but provides ambiguous flattened version boundaries; confirm exact affected builds against vendor advisories and the referenced stable commits.
Exploitation context
The CVSS vector describes a local, low-complexity attack requiring low privileges and no user interaction. Triggering involves an unlikely file-descriptor-exhaustion error path. The bundle reports no CISA KEV listing and provides no evidence of active exploitation or public weaponization.
Researcher notes
The key condition is erroneous cleanup after dma_buf_export()-related processing encounters file descriptor exhaustion. The resulting reference-count imbalance can lead to double-free behavior. The supplied data does not establish practical exploitability, affected distribution packages, indicators of compromise, or complete version boundaries.
Mitigation direction
- Update to a vendor-supported kernel containing the referenced stable correction.
- Confirm your distribution’s package maps to one of the cited fixing commits.
- Restrict untrusted local access to exposed VFIO PCI functionality where operationally feasible.
- Monitor Linux vendor guidance for clarified affected-version boundaries.
Validation and detection
- Inventory kernel versions on systems providing VFIO PCI functionality.
- Determine whether the VFIO PCI dma-buf feature is enabled or used.
- Compare kernel source or vendor package metadata with the cited fixing commits.
- Review relevant reliability events for memory corruption or VFIO-related failures without treating them as proof of exploitation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2026-31468 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/83ad334afc9a645cef1062f5346526b1e36d6516CVE reference, Linux
- https://git.kernel.org/stable/c/e98137f0a874ab36d0946de4707aa48cb7137d1cCVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.